The present invention relates to heat curable compositions comprising a cationically polymerizable organic material, for example, an epoxy resin, a dialkyl hydroxyarylsulfonium salt and an organic oxidant.
As shown in my U.S. Pat. No. 4,216,288, organic resins, for example, epoxy resins can be thermally cured by using an effective amount of an aromatic onium salt such as an aryl iodonium salt and a reducing agent, for example, a thiophenol. The present invention is based on the discovery that such organic resin also can be thermally cured with an organic oxidant, such as an organic peroxide in combination with an effective amount of certain hydroxyaryldialkyl sulfonium salts, for example, ##STR1## dimethyl-4-hydroxy-3,5-dimethylphenyl sulfonium hexafluoroarsenate.